求解一道OG题~

xlylx

For over two centuries, no one had been able to make Damascus blades—blades with a distinctive serpentine surface pattern—but a contemporary sword maker may just have rediscovered how. Using iron with trace impurities that precisely matched those present in the iron used in historic Damascus blades, this contemporary sword maker seems to have finally hit on an intricate process by which he can produce a blade indistinguishable from a true Damascus blade.

Which of the following, if true, provides the strongest support for the hypothesis that trace impurities in the iron are essential for the production of Damascus blades?
A There are surface features of every Damascus blade—including the blades produced by the contemporary sword maker—that are unique to that blade.
B The iron with which the contemporary sword maker made Damascus blades came from a source of iron that was unknown two centuries ago.
C Almost all the tools used by the contemporary sword maker were updated versions of tools that were used by sword makers over two centuries ago.
D Production of Damascus blades by sword makers of the past ceased abruptly after those sword makers’ original source of iron became exhausted.
E Although Damascus blades were renowned for maintaining a sharp edge, the blade made by the contemporary sword maker suggests that they may have maintained their edge less well than blades made using what is now the standard process for making blades.
答案是D
没太理清这道题的逻辑~求大神解答

长发蒲公英666

问--Which of the following, if true, provides the strongest support for the hypothesis that
trace impurities in the iron are essential for the production of Damascus blades?
--Production of Damascus blades by sword makers of the past ceased abruptly after
those sword makers’ original source of iron became exhausted. 在刀剑制造者最初的铁源耗尽之后，过去的刀剑制造者的大马士革刀锋突然停止生产。
（因为原料耗尽，所以没法生产，也就是说只有特定的铁才能生产，别的铁不行。）

错误选项分析—
A. There are surface features of every Damascus blade—including the blades produced
by the contemporary sword maker—that are unique to that blade. 每个大马士革的剑刃都有它的表面特征，包括现代剑刃所产生的刀刃，这是剑刃的独特之处。
表面特征与铁无关，排除。
B. The iron with which the contemporary sword maker made Damascus blades came
from a source of iron that was unknown two centuries ago.
当代剑制造者制造大马士革叶片的铁来自于两个世纪前未知的铁源。来源≠必要，排除。
C. Almost all the tools used by the contemporary sword maker were updated versions
of tools that were used by sword makers over two centuries ago. 几乎所有当代剑器使用的工具都是两个世纪前被刀剑制造者使用的工具的更新版本。讨论工具，无关项，排除。
E. Although Damascus blades were renowned for maintaining a sharp edge, the blade
made by the contemporary sword maker suggests that they may have maintained
their edge less well than blades made using what is now the standard process for
making blades. 虽然大马士革的刀刃以保持锋利的边缘而闻名，但现代剑刃制造者制造的刀刃表明，他们的刀刃可能比用现在标准的制造刀刃的刀刃要锋利得多。比较刀刃，无光，排除。

xlylx

长发蒲公英666 发表于 2017-10-6 08:29
问--Which of the following, if true, provides the strongest support for the hypothesis that
trace im ...

谢谢谢谢！解答得太清晰了